large goldfish/cold fresh water tank HELP ASAP!!

This is a discussion on large goldfish/cold fresh water tank HELP ASAP!! within the Beginner Freshwater Aquarium forums, part of the Freshwater Fish and Aquariums category; -->
me and my bro cleaned out his 5foot X 3foot tank yesturday, the plan was to fill it up with water from the hose ...

me and my bro cleaned out his 5foot X 3foot tank yesturday, the plan was to fill it up with water from the hose put in some gravel by some goldfish and away we go,....we looked into it AFTER buying the goldfish and realised that we have overlooked many things.

so at the moment i am concerned about:

1.ph level in the water
2.oxgyen levels because its a large tank (we have pumps with airstoned from an old aquarium so that should be cool).
3. the gravel we used is for cacti plants!!! not fish aquariums? my bro is very stuborn and never listens to anything i say because im younger then him so its his way or no way at all. anyway i tried to tell him that its colord sand and it might not be good for the fish/water, so we rinsed it out in a bucket 3 or 4 times.

now the tank is full of water and the fish are in a smaller tank for the moment.

i know i need things like ph tester and filter, but i just feel that we rushed into it really quickly and i dont want the fish to die. esepcially with my know it all older brother telling me everything i suggest is wrong.

i dont even know what advice to ask for just help!
any comments would be great, thanks!@

p.s the reason why im freaking out is because my girlfriend payed for the fish yesturday and she loves animals so if anything happens to them....well put it this way, i wont be happy for a very long time if you know what i mean.

Any pictures on the gravel? Buy API liquid test kit and test your ammonia, nitrites, nitrates and pH daily. Do daily water changes until you get your ammonia and nitrites to zero. Ammonia and nitrites are toxic to the fish. Cycling instructions are available in the sticky thread by fish_4_all.